South Carolina defensive end Jadeveon Clowney is playing for a national championship contender, appears to be a lock for the No. 1 pick in the 2014 NFL draft and is generally regarded as the best player in college football, regardless of position.

For all of his assets, Clowney — whose season debut comes Thursday at 6 p.m. ET against North Carolina — has one attribute unbecoming of a Heisman winner. He is exclusively a defensive player.

Full-time defenders such as Notre Dame's Manti Te'o (2012), Pittsburgh's Hugh Green (1980) and Iowa's Alex Karras (1957) finished as runners-up, but only Michigan's Charles Woodson (1997) has broken through to win — and much of his campaign was built on his offensive cameos and an odd case of Peyton Manning fatigue among voters.

Asked what it would take for a defensive player to win the award, Nebraska coach Bo Pelini said, "Something pretty extraordinary. I think there have been some guys that have been probably pretty capable of winning it and have had that type of year, but it's always been kind of an offensive award."

Jadeveon Clowney and the Gamecocks open their season Thursday against North Carolina.(Photo: Kim Klement, USA TODAY Sports)

Pelini offered the example of former Cornhuskers defensive lineman Ndamukong Suh, considered by Pelini and others to be college football's best player in 2009 but who could only muster a fourth-place Heisman finish.

Ohio State coach Urban Meyer said he has coached numerous defensive players he considered to be great but who never factored into the Heisman voting. But Meyer said Clowney has a chance. Clowney emerged as a candidate this preseason partly because of another key trait of Heisman winners: a Heisman moment. His helmet-popping hit on Michigan's Vincent Smith in the Outback Bowl on Jan. 1 has put him in the 2013 Heisman conversation even though it happened in the final game of his 2012 season.

"From the highlights I've seen from the guy from South Carolina, if there's ever going to be one, this is a year he'd be in the race," Meyer said. "I think it will be difficult, but I'm all for it if he's the best player in college football."

QB AJ McCarron, Alabama: Coach Nick Saban could be willing to open up his offense with several key losses on the offensive line. That should help his quarterback post more impressive statistics, making him a Heisman threat.
John David Mercer, USA TODAY Sports

WR Marqise Lee, USC:
Lee, who finished fourth last year, posted 1,721 yards on 118 receptions with 14 touchdowns and is a game-breaker waiting to happen, but he won’t have Matt Barkley throwing to him.
Robert Hanashiro, USA TODAY

QB Jordan Lynch, Northern Illinois: Lynch set an NCAA record for rushing yards by a quarterback with 1,815 (and also scored 19 TDs) and threw for 3,138 yards with 25 touchdown passes and six interceptions.
Andrew Weber, USA TODAY Sports

QB Teddy Bridgewater, Louisville: Bridgewater is being talked about as the top quarterback prospect in next year’s NFL draft. But first, Bridgewater will lead the Cardinals in the first year of the American Athletic Conference.
Chuck Cook, USA TODAY Sports

RB Duke Johnson, Miami (Fla.): Johnson posted the second-most all-purpose yards in a season at Miami with 2,060 as a freshman. He also set a freshman record with 947 rushing yards.
Mark Dolejs, USA TODAY Sports

RB De'Anthony Thomas, Oregon: Thomas presents a bit of a wild card, given that he will be playing for a new coach and is in the Pac-12 with a lot of night games after voters in the Eastern half of the country have gone to bed.
Kirby Lee, USA TODAY Sports